Occlusion apparatus

ABSTRACT

Methods, apparatus, and systems for occluding a left atrial appendage are provided. One embodiment includes an elongate body having a tissue apposition member extendably positioned within a lumen of the elongate body to appose tissue of the LAA. An energy emitting device coupled to the elongate body can be used for emitting high intensity focused ultrasound to the tissues to fuse the tissues.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/209,191, filed Aug. 12, 2011, now abandoned, which is a continuationof Ser. No. 12/917,287, filed Nov. 1, 2010, now U.S. Pat. No. 7,998,138,which in turn is a divisional of U.S. patent application Ser. No.11/207,271, filed Aug. 19, 2005, now U.S. Pat. No. 7,824,397; thecontents of each are hereby incorporated by reference.

FIELD OF THE INVENTION

The present disclosure relates generally to apparatus, systems, andmethods for use in the human body, more particularly to apparatus,systems, and methods to close an opening of a left atrial appendage inthe heart.

BACKGROUND

The human heart is divided into four chambers. These include the rightatrium, the right ventricle, the left atrium, and the left ventricle.The right atrium and right ventricle are divided from the left atriumand left ventricle by a muscular wall called the septum. The atrialseptum is the wall separating the atria and the ventricular septum isthe wall separating the ventricles.

Both the right and left atrium have a pouchlike structure attached tothe atrium, which is called the right atrial appendage and the leftatrial appendage (LAA). The LAA is the remnant of the original embryonicleft atrium that develops during the third week of gestation. The LAA isa long, tubular, hooked structure which is usually crenellated and has anarrow junction with the venous component of the atrium.

In adults, there are no known uses for the left and right atrialappendages, like the appendix in the intestines. In the normal heart,the appendages contract, along with the rest of the atrial muscle andthe blood moves in and out of the atrial appendages. In atrialfibrillation, there is a lack of synchronous or uniform contraction ofthe atrium muscle. Thus, the blood in the appendages remains dormant anddoes not move. In the right atrium, this has not been a health problem.In the LAA however, dormant blood can cause health problems. When theblood remains dormant in the LAA, thrombus has a tendency to form. Insome patients, thrombus in the LAA can leave and travel within thecardiovascular system. In some instances, thrombus can travel to thebrain and result in a stroke.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective view of the heart is shown.

FIG. 2 illustrates an embodiment of an occlusion apparatus according tothe teachings of the present disclosure.

FIGS. 3A-3G illustrates various embodiments of a tissue appositionmember according to the teachings of the present disclosure.

FIG. 4 illustrates an embodiment of a system of the present disclosure.

FIG. 5A-5E illustrates various embodiments of a method to fuse tissue ofthe left atrial appendage.

FIGS. 6A-6C illustrates various embodiments of another method to fusetissue of the left atrial appendage.

DETAILED DESCRIPTION

Embodiments of the present disclosure are directed to methods,apparatus, and systems for apposing tissues of the left atrial appendageand fusing the tissues to occlude the opening of the LAA. For example,in various embodiments, apposing and fusing tissues of the LAA can beaccomplished through the use of a catheter delivered to the left atrium.In various embodiments, once the catheter is properly positioned withinthe left atrium, a tissue apposition member can be extended from thecatheter and an apposition arm positioned within the tissue appositionmember can be used to manipulate the tissue of the LAA so as to bringthe tissue together. In another embodiment, once the catheter isproperly positioned within the left atrium, a closure sheath can beretracted to release an apposition arm held in compression by theclosure sheath in a collapsed state such that the apposition arm canspring toward an expanded state to engage tissue and bring the tissuetogether. In various embodiments, an energy emitting device can be usedto apply ultrasound focused to a high intensity to the tissues so as tofuse the tissues together and close the LAA.

In various embodiments of FIGS. 3A-3G, components can include appositionarms (e.g., apposition arms 340-1 and 340-2 illustrated in FIG. 3A). Invarious embodiments, the apposition arms can be positioned within alumen of the tissue apposition member 328 in a manner that allows themto engage various tissues, such as tissue of an LAA, through variousengaging mechanisms such as pushing, springing, expanding, etc., andother engaging mechanisms. For example, in various embodiments of FIGS.3A and 3C, deployment rods 350, 350-1 and 350-2 can be utilized to pushapposition arms 340-1 and 340-2 within lumens 336-1 and 336-2 andthrough opening 338-1 and 338-2 to engage tissue of an LAA.

As will be discussed herein, in the various embodiments of the presentdisclosure, tissues can be brought together before, during, and/or afterapplying energy to the tissues. The use of focused ultrasound and othertypes of energy (e.g., RF energy) on tissues denatures the collagen inthe tissue. Tissues that undergo denaturization will tend to renature.If tissues brought together remain in contact while they renature, thecollagen in the tissues brought together will effectively combine tofuse the once separated tissues together.

The method, apparatus, and system embodiments described herein areillustrated with reference to fusing tissue of the LAA to occlude anopening of the LAA. However, the method, apparatus, and systemembodiments can also be used to fuse other tissues and thus, occludeother openings. For example, using the various method, apparatus, andsystem embodiments described herein, various defective occlusions suchas patent ductus arteriosus (PDA), atrial septal defects (ASDs), andventricular septal defects (VSDs) can be occluded.

In FIG. 1, a perspective view of the heart 100 is shown. As noted above,the heart 100 is divided into four chambers, which are referred toherein as the right atrium 102, a right ventricle, a left atrium 104 anda left ventricle. Heart 100 also includes a septal wall 106 that dividesthe four chambers of the heart 100. The portion of the septal walldividing the left and right atriums 102 and 104 is called theinteratrial septum. The portion of the septal wall 106 dividing the leftand right ventricle is called the ventricular septum. The fossa ovalis110 is an oval depression on the septal wall 106 of the interatrialseptum 108, and corresponds to the situation of the foramen ovale (i.e.,the communication between the right and left atria in the fetal heart).As will be discussed herein, the various apparatus, system, and methodembodiments utilized to fuse the LAA can gain access to the LAA byentering the right atrium and advancing through tissue adjacent to thefossa ovalis 110 to enter the left atrium or advancing through a passageadjacent to the fossa ovalis 510.

FIG. 2 illustrates an embodiment of an occlusion apparatus 212 accordingto the teachings of the present disclosure. In various embodiments, theocclusion apparatus 212 includes a catheter 213 having an elongate body214 with a proximal end 216 a distal end 218. In various embodiments,the elongate body 214 can include a number of lumens. In the embodimentof FIG. 2, the elongate body 214 includes a first lumen 220, a secondlumen 222, and a guidewire lumen 224. In various embodiments, each lumen220, 222, and 224 can extend from the proximal end 220 toward the distalend 222 of the elongate body 214. In various embodiments, each lumen220, 222, and 224 can include various configurations. For example, insome embodiments, the guidewire lumen 224, the first lumen 220 and thesecond lumen 224 can include a tri-lumen configuration within thecatheter 213, as shown in FIG. 2. In other embodiments, the lumens ofthe catheter can include a coaxial lumen design (e.g., lumen within alumen).

In various embodiments, the first lumen 220, the second lumen 222, andthe guidewire lumen 224 of the elongate body 214 can house a number ofcomponents of the occlusion apparatus 212. For example, in variousembodiments, the guidewire lumen 224 can receive a guidewire 226 forpositioning the occlusion apparatus 212 within a heart chamber e.g., aleft atrium of a patient. In some embodiments, the guidewire can includea lumen and a pointed tip for piercing tissue adjacent the fossa ovalisto gain entry to the left atrium and to inject contrast media into theleft atrium, as will be discussed herein with respect to FIG. 5A.

In various embodiments, the first lumen 220 of the elongate body 214 caninclude a tissue apposition member 228. The tissue apposition member 228can be extendably positioned at least partially within the first lumen220 of the elongate body 214. In various embodiments, the tissueapposition member 228 can include various components that can be used tobring tissues of a left atrial appendage together, as discussed belowwith respect to FIGS. 3A-3G.

FIGS. 3A-3G illustrate various embodiments of the tissue appositionmember 328 of the present disclosure. In various embodiments of FIGS.3A-3G, the tissue apposition member 328 includes an elongate body 330having a proximal end 332 and a distal end 334. In various embodiments,the elongate body 330 can include various geometric shapes including,but no limited to, circular, ovular, polygonal, and irregular geometricshapes. The elongate body 330 of the tissue apposition member 328 can beconstructed from a number of materials. In some embodiments, thematerials used to form the elongate body can be rigid, semi-flexible, orflexible. Examples of materials include, but are not limited to, metal,metal alloys, shape memory metals, polymeric materials including shapememory polymers, natural and synthetic materials, and others.

In various embodiments, the tissue apposition member 328 can include anumber of lumens extending between the proximal and the distal end 332and 334. In some embodiments, the tissue apposition member 328 caninclude a single lumen, and in other embodiments, the tissue appositionmember can include two or more lumens. In various embodiments, thelumens of the tissue apposition member can include an independentconfiguration, e.g., a dual lumen configuration as shown in theembodiment of FIGS. 3A, 3B, and 3D. In some embodiments, the lumens ofthe tissue apposition member 328 can include a coaxial configuration.

The lumens of the tissue apposition member can house various componentsthat can be extended, and/or retracted within the tissue appositionmember 328 through one or more openings in the tissue apposition member328. In some embodiments, components of the tissue apposition member canbe released from the tissue apposition member 328 after they haveengaged tissue within the human body. In addition, in variousembodiments, components can be used to manipulate tissues within thehuman body, e.g., to bring tissues together.

In various embodiments of FIGS. 3A-3G, components can include appositionarms (e.g., apposition arms 340-1 and 340-2 illustrated in FIG. 3A). Invarious embodiments, the apposition arms can be positioned within alumen of the tissue apposition member 328 in a manner that allows themto engage various tissues, such as tissue of an LAA, through variousengaging mechanisms such as pushing, springing, expanding, etc., andother engaging mechanisms. For example, in various embodiments of FIGS.3A and 3C, deployment rods 350, 350-1 and 350-2 can be utilized to pushapposition arms 340-1 and 3402 within lumens 336-1 and 336-2 and throughopening 338-1 and 338-2 to engage tissue of an LAA.

In another example, apposition arms of tissue apposition member 328,such as apposition arms 340-1 and 340-2 illustrated in FIG. 3E, can beformed of a resilient material and compressed within lumen 331 of the aclosure sheath 329. In such embodiments, when the compression isreleased, such as when the closure sheath 329 is retracted, theapposition arms 340-1 and 340-2 are no longer held in compression andcan spring toward a biased direction radially from a longitudinal axisof the tissue apparatus member 328. These and other embodiments will bediscussed in more detail in FIGS. 3A-3E and 5A-5F.

According to various embodiments illustrated in FIGS. 3A-3E, appositionarms can include a variety of predefined shapes and sizes that allow forthe apposition arms to engage tissue, such as tissue of the LAA. Invarious embodiments, engaging tissue can include clamping, grasping,gripping, hooking, piercing, lodging, catching, vacuuming, pushing,pulling, and/or trapping such that the tissue can be brought together orotherwise manipulated. In various embodiments, engaging tissue can alsoinclude various engaging mechanisms such as springing, pushing, andpulling, among others.

For example, n various embodiments of FIG. 3A, the tissue appositionmember 328 can include a first lumen 336-1 and a second lumen 336-2 incommunication with a first opening 338-1 and a second opening 338-2. Thefirst and second lumen 336-1 and 336-2 extend from the proximal end 332toward the distal end 334 of the tissue apposition member 328. Invarious embodiments, the first and second lumen 336-1 and 336-2 can bedesigned to accommodate a number of components, e.g., apposition arms340-1 and 340-2 and deployment rods 350-1 and 350-2.

In various embodiments, the deployment rods 350-1 and 350-2 can beformed of a resilient material that allows the deployment rods to flex,bend, and rotate when deployed from the distal end of the tissueapposition member, as will be discussed below with respect to FIGS.5A-5E. The deployment rods can be releasably coupled to the appositionarms 340-1 and 340-2 and can be used by an operator to manipulate theapposition arms 340-1 and 340-2. In various embodiments, manipulatingthe apposition arms 340-1 and 340-2 can include engaging the tissues ofthe LAA by pushing the apposition arms such that hooking structures346-1 and 346-2 at the distal end 344 of the apposition arms 340-1 and340-2 pierce and hook the tissues. Once engaged, the apposition arms340-1 and 340-2 can be pulled by an operator to bring the tissuestogether.

In another embodiment, the tissues of the LAA can be brought together bysliding a closure sheath 229 along a longitudinal axis of the tissueapposition member 328 to draw the engaged apposition members 340-1 and340-2 together and thereby, bring tissue engaged to the apposition arms340-1 and 340-2 together, as will be discussed with respect to FIGS.3E-3G, and 6A-6C.

In various embodiments, it may be desirable to leave the apposition arms340-1 and 340-2 within engaged tissue. In such embodiments, thedeployment rods 350-1 and 350-2 can be used to release the appositionarms 340-1 and 340-2 from the tissue apposition member 328 such that theapposition arms 340-1 and 340-2 remain lodged within the tissue.

FIG. 3B illustrates another embodiment of the tissue apposition member328. In the embodiment of FIG. 3B, the tissue apposition member 328includes the first and second apposition arms 340-1 and 340-2. Theapposition arms 340-1 and 340-2 illustrated in FIG. 3B include agrasping structures 348-1 and 348-2 at the distal end 344 of theapposition arms 340-1 and 340-2. In various embodiments of FIG. 3B, theapposition arms 340-1 and 340-2 can extend radially from the tissueapposition member 328 through openings 338-1 and 338-2. The graspingstructure 348 allows the apposition arms 340-1 and 340-2 to grasp thetissues of the LAA such that the tissue can be pulled by an operatormanipulating the apposition arms 340-1 and 340-2 to bring the tissuestogether. Similarly, in various embodiments, the apposition arms 340-1and 340-2 can bring tissue together by extending a closure sheathlongitudinally over the tissue apposition member to draw the appositionarms together 340-1 and 340-2, as will be discussed in more detail withrespect to FIGS. 5A-5F.

FIG. 3C illustrates an embodiment of the tissue apposition member 328having a lumen 336 and two apposition arms 340-1 and 340-2 that divergeat a base 341 of the apposition arms 340-1 and 340-2. In variousembodiments, the apposition arms 340-1 and 340-2 can be extendably andreleasably positioned within the lumen 336. In the embodiment of FIG.3C, the apposition arms 340-1 and 340-2 diverge from the base 342 andextend radially relative to a longitudinal axis of the tissue appositionmember 328. In this embodiment, the apposition arms 340-1 and 340-2include hooking structures 346-1 and 346-2 at the distal end 344 of theapposition arm 340. In various embodiments, the apposition arms 340-1and 340-2 can be releasably coupled to the base 341. In suchembodiments, the apposition arms can be released from the base 341 suchas when they have engage tissue and are to be left within the engagedtissue.

In various embodiments, the apposition arms 340-1 and 340-2 can bemanipulated using a deployment rod 350 to engage tissue of the LAA bypiercing and hooking the tissue with the first and second hookingstructures 346-1 and 346-2 to bring them together. In some embodiments,the apposition arms can be formed of a resilient material that providesthe apposition arms with spring like properties that allow the hookingstructures to pierce and hook tissue of the LAA without manipulating theapposition arms with the deployment rod 350, as will be discussed withrespect to FIGS. 3E-3G.

FIGS. 3E-3G illustrates an embodiment of the tissue apposition membersimilar to tissue apposition member 328 illustrated in FIG. 3C. Invarious embodiments, tissue apposition member 328 can be slidablypositioned within a closure sheath 329. In various embodiments, theclosure sheath 329 can include a proximal end 343 and a distal end 345.In various embodiments, the distal end 345 of the closure sheath 329 caninclude an opening 347 in communication with a lumen 331 of the closuresheath 329. In various embodiments, the closure sheath can be formed toinclude a lubricous inner surface 333 and outer surface 335 to providefor the slidability of the closure sheath 329 within a lumen of acatheter and along an outer surface of the tissue apposition member 328.

As shown in FIG. 3E, the apposition arms 340-1 and 340-2 include thebase 341. The base 341 of the apposition arms 340-1 and 340-2 ispositioned within lumen 336 of the tissue apposition member 328 and canextend along the length of the tissue apposition member 328 from thedistal end 334 to the proximal end 332. In some embodiments, the base342 can extend from the lumen 336 at the proximal end 332 such that theapposition arms 340-1 and 340-2 can be manipulated by an operator. Invarious embodiments, the apposition arms 340-1 and 340-2 and hookingstructures 346-1 and 346-2 are positioned within lumen 331 of theclosure catheter 329. In this embodiment, the apposition arms 340-1 and340-2 are in a collapsed state (i.e., held in compression by innersurface 333 of lumen 331 of the closure sheath 329).

As shown in FIG. 3F, the apposition arms 340-1 and 340-2 are in anexpanded state. In various embodiments, the closure sheath 329 can beretracted toward the proximal end 332 of the elongate body 330 of thetissue apposition member 328 to release the apposition arms 340-1 and340-2. When the apposition arms are released 340-1 and 340-2, theyspring radially away from a longitudinal axis 337 of the tissueapposition member 328 in various directions. In such embodiments, thespring like properties of the apposition arms 340-1 and 340-2 can engagetissue of the LAA by piercing and hooking the tissue with the hookingstructures 346-1 and 346-2 when the apposition arms 340-1 and 340-2 arereleased adjacent to or proximal to such tissues.

Referring now to FIG. 3F, in various embodiments, the closure sheath 329can be used to draw apposition arms 340-1 and 340-2 together by slidingthe closure sheath 329 along the longitudinal axis 337 of the tissueapposition member 328 toward the hooking structures 346-1 and 346-2 suchthat the inner surface 333 of the closure sheath 329 compresses theapposition arms 340-1 and 340-2 toward each other. In variousembodiments, the longitudinal axis 337 of the tissue apposition member328 can provide a guide for the closure sheath 329 to draw theapposition arms 340-1 and 340-2 together. In such embodiments, tissue ofthe LAA engaged to the apposition arms can be brought together, as willbe discussed in FIGS. 6A-6C.

In various embodiments, the apposition arms can be formed of variousmaterials that provide spring like (i.e., elastic) properties to theapposition arms. Examples of suitable materials for forming theapposition arms can include, but are not limited to, metals, metalalloys, and/or polymer materials. Specific examples of such materialscan include shape memory metals such as Nitinol, linear-elastic Nitinol,super-elastic Nitinol, shape memory polymers, medical grade stainlesssteel (e.g., 316L), titanium, tantalum, platinum alloys, niobium alloys,cobalt alloys, alginate, MP35N, aluminum alloys, chromium alloys, copperalloys, vanadium alloys, or combinations thereof. Examples of plasticscan include shape memory plastics, polymers, and thermoplasticmaterials. Other materials are also contemplated.

These materials can allow for forming and setting the expanded state inthe arms 340-1 and 340-2 that can resiliently flex to be compressedwithin the lumen 331 of the closure sheath 329 and then spring towardtheir expanded shape when the arms 340-1 and 340-2 are released from thelumen 331, such as when the closure sheath 329 is retracted.

In various embodiments, the apposition arms, can be releasably coupledto the tissue apposition member 328 such that they can be released fromthe tissue apposition member 328 and left in the human body. In suchembodiments, the apposition arms can be released using a number ofmechanical or chemical mechanisms. For example, in various embodiments,a deployment rod can be coupled to an apposition arm by threading thedeployment rod to the apposition arm. In such embodiments, thedeployment rod can release the apposition arm by unthreading theapposition arm. In another embodiment, the deployment rod can be coupledto the apposition arm by a chemical adhesive. In such an embodiment, thedeployment rod can be released from the apposition arm by heating theadhesive and/or applying a sufficient force to the deployment such thatthe chemical bond holding the deployment rod to the apposition armbreaks.

In embodiments where the apposition arms are released from the tissueapposition member and left behind in the human body, the apposition armscan be formed of bioabsorbable materials that can degrade and beabsorbed by the human body after a period of time. Examples ofbioabsorbable materials include, but are not limited to, polycarboxylicacid, polyanhydrides including maleic anhydride polymers;polyorthoesters; poly-amino acids; polyethylene oxide; polyphosphazenes;polyactic acid, polyglycolic acid and copolymers and copolymers andmixtures thereof such as poly(L-lactic acid) (PLLA), poly(D,L,-lactide), poly(lactic acid-co-glycolic acid), 50/50(DL-lactide-co-glycolide); polydioxanone; polypropylene fumarate;polydepsipeptides; polycaprolactone and co-polymers and mixtures thereofsuch as poly(D,L-lactide-co-caprolactone) and polycaprolactoneco-butylacrylate; polyhydroxybutyrate valerate and blends;polycarbonates such as tyrosine-derived polycarbonates and arylates,polyiminocaronates, and polydimethyltrimethylcarbonates; cyanoacrylate;calcium phosphates; polyglycosaminoglycans; macromolecules such aspolysaccharides (including hyaluronic acid, cellulose, andhydroxypropylmethyl cellulose; gelatin; starches; dextrans; alginatesand derivatives thereof), proteins and polypeptides; and mixtures andcopolymers of any of the foregoing. The biodegradable polymer may alsobe a surface erodable polymer such as polyhydroxybutyrate and itscopolymers, polycaprolactone, polyanhydrides (both crystalline andamorphous), maleic anhydride copolymers, and zinc-calcium phosphate.

Referring now to FIG. 3D, another embodiment of the tissue appositionmember 328 is illustrated. In the embodiment of FIG. 3D, the tissueapposition member 328 includes a first suction arm 352-1 and a secondsuction arm 352-2 that can be extendably positioned within the first andsecond lumens 336-1 and 336-2 of the tissue apposition member 328. Inthe embodiment of FIG. 3D, the suction arms 352-1 and 352-2 can extendradially from the tissue apposition member 328 through openings 338-1and 338-2. In such embodiments, suction arms 352-1 and 352-2 can bepositioned adjacent tissues of the LAA and a vacuum can be applied tothe tissues to cause the tissues to attach to the suction arms 352-1 and352-2. Once the tissues are attached, an operator can manipulate thesuction arms, e.g., retract the suction arms, to bring the tissuestogether or otherwise maneuver their position, as will be discussedherein.

In various embodiments, the suction arms 352-1 and 352-2 can be attachedto a vacuum element located outside the human body which can be used tocreate the vacuum. In various embodiments, the suction arms 352-1 and352-2 can be formed of a variety of materials including, but not limitedto, metal, metal alloys, shape memory metals, polymeric materialsincluding shape memory polymers, natural and synthetic materials, andothers.

Referring again to FIG. 2, the elongate body 214 of catheter 213includes the second lumen 222. Second lumen 222 extends from theproximal 216 end to the distal end 218 of the catheter 213. In variousembodiments, the energy emitting device can be operatively coupled tothe catheter and can be extendably positioned within the second lumen222. As used herein, operatively coupled means that the energy emittingdevice 254 includes the necessary components, e.g., power source,conductors, software, computer, and other components that can beconnected to the energy emitting device in a wireless and/or wiredfashion to allow the energy emitting device to properly function. Asused herein, an energy emitting device 254 is a device that can emitvarious types of energy including, but not limited to, high intensityfocused ultrasound (HIFU), low intensity ultrasound (e.g., imagingultrasound), RF energy, cryogenic energy, laser, resistive heat energy,and microwave. In various embodiments, the energy emitting device can bedesigned to emit more than one type of energy. For example, in someembodiments, energy emitting device 254 can be configured to emit highintensity focused ultrasound and low intensity ultrasound. As usedherein, energy emitting devices 254 may have a number of differentconfigurations, which can depend on the type of device, its placementlocation relative to the occlusion apparatus (e.g., on or physicallyseparate from the occlusion apparatus), as well as its intendedoperational methods. For example, in some embodiments, the energyemitting device 254 can include a high intensity focused ultrasound(HIFU) transducer operatively coupled to the occlusion apparatus 212, asshown in the embodiment of FIG. 2. In such embodiments, the energyemitting device 254 is configured to emit HIFU to a target from withinthe human body. In other embodiments, such as in the embodimentillustrated in FIG. 4, the energy emitting device 254 is configured toemit the HIFU from outside the human body to a target located inside thehuman body.

According to various embodiments, the HIFU transducer 256 can be formedof a number of piezoelectric materials that can deform and emit HIFUwhen an electrical potential is supplied to the HIFU transducer 256. TheHIFU transducer can include insulating material, and conductive materialso as to protect the HIFU from the heat and to electrically coupleconductors to the HIFU transducer 256. In the embodiment of FIG. 2, theHIFU transducer is shown coupled to conductors 258-1 and 258-2 isolatedfrom each other by an insulating coating. The conductors 258-1 and 258-2extend from the distal end 218 of the catheter 213 to the proximal end216 and from the proximal end 216 to a signal generator 260 and anamplifier 262 outside the catheter 213. In various embodiments, anelectrical signal from the signal generator 260 can be sent along theconductors 258-1 and 258-2, which generates electrical potential acrossthe HIFU transducer 256. The electrical potential causes the HIFUtransducer to deform in response to the changing potential and emitHIFU.

In various embodiments, the HIFU transducer 256 can be shaped andpositioned in a mariner that gives the emitted HIFU directionality. Forexample, in the embodiment illustrated in FIG. 2, the HIFU transducerhas a concave shape and is therefore, able to focus the HIFU in aforward direction to a focal point. As will be discussed herein, thefocal point of the HIFU can include tissue of the LAA that is to befused together. In various embodiments, the HIFU transducer 256 may bemade of various materials having piezoelectric characteristics. Exampleof suitable materials can include, but are not limited to, piezoelectriczirconium titanate (PZT) and polyvinylidene difluoride (PVDF), amongothers. HIFU can be produced at the focal point by thermal and/orcavitation effects or a combination of thermal and cavitation effectscaused by focused application of piezoelectric-generated high-intensityfocused ultrasound.

In various embodiments, the occlusion apparatus can include a targetingdevice, such as targeting device 468 illustrated and described in FIG.4. In various embodiments, the targeting device can be physicallyseparate from the occlusion apparatus. In some embodiments, thetargeting device can be coupled to the occlusion apparatus. In addition,various components such as processors, circuits, computer executableinstructions (e.g., software), etc., can be used in conjunction with theocclusion apparatus 212 and the targeting device, as will also bediscussed in more detail below with respect to FIG. 4.

In one embodiment, the targeting device (e.g., 468 in FIG. 4) can beoperatively coupled to a portion of the elongate body of catheter. Invarious embodiments, the targeting device can include a low intensityimaging ultrasound device configured to locate a target and guide thehigh intensity focused ultrasound to a target from within the humanbody. The targeting device can be coupled to a signal generator andother hardware configured to provide low intensity imaging ultrasoundsignals to the imaging ultrasound device. In various embodiments, signalgenerator 260 can be configured to provide low intensity imagingultrasound signals. In various embodiments, an electrical signal fromthe signal generator can be sent along conductors coupled to the lowintensity imaging ultrasound device to create a signal potential acrossa transducer of the low intensity ultrasound imaging device. Asdiscussed above, the signal potential causes the low intensityultrasound transducer to deform in response to the changing potentialand emit low intensity imaging ultrasound signals. The low intensityimaging ultrasound signals can then be processed to create and/or locatea target and provide an image of the target on a display screen, as willbe discussed below in FIG. 4.

FIG. 4 illustrates an embodiment of a high intensity focused ultrasoundsystem 464. In various embodiments, the system 464 can include acatheter 413. The catheter 413 includes an elongate body 414 having aproximal end 416 and a distal end 418. The catheter 413 includes lumen420 extending from the proximal end 416 to the distal end 418 of thecatheter 413.

In various embodiments, the system 464 can include the closure sheath429, as the same has been illustrated and described herein. The closuresheath 429 can be slidably coupled within the first lumen 420 of theelongate body 414, as shown in FIG. 4.

In various embodiments, the system 464 can include a tissue appositionmember 428, as the same has been described herein. The tissue appositionmember 428 can travel within lumen 431 of closure sheath 429 along thelength of the catheter 413 and extend radially from an opening in thecatheter 413 at the distal end 418, as shown FIG. 4.

The catheter 413 can further include the guidewire lumen 424. Theguidewire lumen 424 can extend within and along the length of theelongate body 414 of the catheter 413 from the proximal end 416 to thedistal end 418 of the catheter 413. In various embodiments, theguidewire lumen 424 can receive the guidewire 426 for positioning thecatheter 413 and the tissue apposition member 428 within a heart chambere.g., a left atrium of a patient, as the same has been described hereinwith respect to FIG. 2. In various embodiments, the guide wire lumen 424and lumen 420 can include various configurations. For example, in someembodiments, the guidewire lumen 424 and the lumen 420 can include adual lumen configuration within the catheter 413, as shown in FIG. 4. Inother embodiments, the guidewire lumen 424 and lumen 420 can include acoaxial configuration within the catheter 413.

As the reader will appreciate, various components of the system 464 canbe operated by directly grasping their proximal ends and manipulatingthem or in the case where deployment rods are used, by directly graspingthe deployment rods to manipulate the components. For example, as shownin the embodiment of FIG. 4, the base 441 of the apposition arms 440-1and 440-2 extend from the proximal end 416 of the catheter 413, as shownin the embodiment of FIG. 4.

In various embodiments, the system 464 can include an energy emittingdevice 454. As shown in the embodiment of FIG. 4, the energy emittingdevice 454 can include a HIFU transducer 456, as the same has beendescribed herein. In the embodiment of FIG. 4, the HIFU transducer 456is configured to emit HIFU from outside the human body to a targetinside the human body. In various embodiments, the HIFU transducer 456is operatively coupled to conductors 458, a signal generator 460,amplifier 462, a computer 469 including computer executable instructions(e.g., software), a targeting device 468, and a display 470, as shown inthe illustration of FIG. 4.

As used herein, the targeting device 468 is a device that can provide,create and/or locate a target to which HIFU emitted from the energyemitting device 343 can be guided, directed, applied, delivered, and thelike. As used herein, a target is a location to which an energy emittingdevice 454 delivers energy, for example, tissues of the LAA. As usedherein, locating a target means visually defining a target using thedisplay screen, e.g., 470, to display an image of tissue in which anoperator can guide HIFU and/or using program instructions executing on acomputer 469 to create a target using trigonometric algorithms (e.g.,triangulation), dynamic depth focusing algorithms, etc., to which theHIFU is directed. For example, locating a target can include visuallyobserving an image of the target (.e.g., an image of tissue) to whichHIFU is to be directed.

In various embodiments, guiding, directing, etc., the HIFU to the targetcan include utilizing the targeting device 468 in conjunction withprogram instructions executing on a computer 469 coupled to thetargeting device 468 and energy emitting device 454 to help guide theHIFU to the target. In such embodiments, guiding the HIFU to the targetcan include a manual process where the physician controls the directionof the HIFU, and other parameters such as frequency, intensity, andfocus of the HIFU. In some embodiments, the energy emitting device andthe targeting device are electrically and communicatively coupled toeach other and include program instructions executable to provideautomated locating and guiding of the high intensity focused ultrasoundto the target. For example, in various embodiments, locating and guidingthe HIFU to the target can include an automated process where mechanicaldevices, such as robotic devices, control the direction of the HIFUincluding the frequency, intensity, and focus, among other parametersinvolved in operating the targeting device 468 and the HIFU transducer456. In such an embodiment, for example, the HIFU transducer 456 can bemotorized and electrically and communicatively coupled to the targetingdevice and other components (e.g., signal generator 260 and amplifier262, among others).

The targeting device 468 can include a single component or multiplecomponents. In various embodiments, the components of the targetingdevice 468 can be located at a target, proximal to a target, and/ordistal to the target. For example, in some embodiments, the targetingdevice 468 can include multiple components where one component islocated adjacent the target, and another component is located distal tothe target. In various embodiments, the targeting device can includeradiopaque markers as one component positioned at or proximal to thetarget along with apposition arms within the human body, as described inFIGS. 3A-3D, and as another component such as a display screenpositioned outside the human body to provide an image of the radiopaquemarkers at or proximal to the target.

Examples of the targeting device 468 and components of the targetingdevice 468 can include, but are not limited to, imaging probes anddevices (e.g., magnetic resonance imaging, ultrasound imaging, opticalimaging), Doppler devices (e.g., Doppler audio), software, computers,dynamic depth focusing devices, targeting markers (e.g., ultrasoundtargeting icons, radiopaque markers), etc. Other devices and componentsof the targeting device can include echogenic, angioscopic, andfluoroscopic visualization techniques. In some embodiments, thetargeting device 468 can include Virtual Reality (VR) systems, andAugmented Reality Systems, where real-time information, such as an imageof a PFO from the patient, is integrated with that from a 3-D model ofthe patient's PFO from a Virtual Reality system. Other visualizationdevices and systems are also contemplated.

In various embodiments, the targeting device 468 can perform otherfunctions such as monitoring the tissue for physical changes, visualchanges, thermal changes, and the like. For example, in variousembodiments, an operator of the targeting device 468 can monitor thetemperature of the tissues of the LAA after HIFU has been applied todetermine if the tissues have sufficiently cooled and whether they havefused together (i.e., renatured). In such embodiments, the targetingdevice 468 can include a monitoring function that provides thermometricimaging and can produce a temperature map of the targeted area, as thesame will be known and understood.

Multiple components can be employed in conjunction with the targetingdevice 468. For example, catheter 413 can include temperature sensorscoupled to the distal end 418 of the catheter 413. In variousembodiments, the tissue apposition member 428 can include temperaturesensors coupled to the tissue apposition member 428 and/or to thecomponents of the catheter (e.g., apposition arms 440, 440-1, and440-2). Embodiments are not limited to these examples.

In various embodiments, the targeting device 468 can be located outsidethe human body. In various embodiments, the targeting device includingother components, e.g., program instruction executing on computers,etc., can be used in conjunction with the occlusion apparatus asdescribed in connection with FIGS. 2, and 3A-3D. In various embodiments,the targeting device can create, locate, and/or guide the HIFU emittedfrom the HIFU transducer 256 coupled to the occlusion apparatus 212 tothe target as described in FIG. 2.

The various embodiments of the targeting device can provide real-timeimages of the target (e.g., via a real-time imaging ultrasound device, areal-time MR imaging device, a real time optical imaging device, etc.).The real-time images can be provided before, during, and/or after theapplication of energy to the target. For example, in variousembodiments, a targeting device that includes a real-time imagingultrasound device can be configured to provide real-time images of atarget, e.g., tissue of an LAA, such that an operator of the energyemitting device can apply energy to the target while simultaneouslyviewing the target. Such embodiments allow the operator to verify thatenergy emitted from the energy emitting device is correctly guided to aparticular target. Such embodiments also provide the operator withreal-time monitoring of changes to tissues induced by the application ofenergy to the tissues while the energy is being applied to the tissues.

FIGS. 5A-5E illustrate embodiments of methods for fusing tissues of aleft atrial appendage by bringing tissues of the LAA together and fusingthe tissues with an energy emitting device located outside the humanbody.

The LAA can be accessed in a number of ways as will be apparent to thoseskilled in the art. As shown in the embodiment of FIG. 5A, accessing theleft atrium can be accomplished by entering the right atrium andpenetrating the fossa ovalis to gain entry to the left atrium. Invarious embodiments, catheter 513 can be positioned within the rightatrium 502 by introducing the catheter 513 into the venous system of thepatient using a minimally invasive percutaneous, transluminal catheterbased delivery system. For example, a guidewire can be positioned withinthe venous system and advanced to the right atrium 502 of a patient. Invarious embodiments, the right atrium 502 can be entered via the orificeof the inferior vena cava 507. The catheter 513 can be positioned overthe guidewire and the catheter advanced so as to position the distal endof the catheter at or adjacent the septal wall of right atrium 502. Aunique aspect of the fossa ovalis 510 is its location relative to theorifice of the inferior vena cava 507. Since the fossa ovalis 510 islocated above and to the left of the orifice of the inferior vena cava507, the catheter 513 can be immediately advanced to the fossa by theuse of the guide wire upon entering the right atrium 502 from theorifice of the inferior vena cava 507. In various embodiments, thetargeting device and various components of the targeting deviceillustrated in FIG. 4 can be utilized to help properly position thecatheter within the right atrium 502 and to help locate the fossa ovalis510. For example, radiopaque markers on the catheter and/or the tissueapposition member can be used to help position the catheter within theright atrium and proximal to or adjacent the fossa ovalis. Radiopauemarkers can also be placed on the various components of the catheter(e.g., apposition arms) to help visualize and manipulate the componentswithin the heart. In addition, orientation and visualization of thecatheter and its various components, e.g., tissue apposition member andapposition arms may be accomplished through the use of any combinationof MR imaging, echogenic, angioscopic, imaging ultrasound andfluoroscopic visualization techniques.

Once the physician has properly positioned the distal end of thecatheter adjacent the fossa ovalis 510, the physician can advance thecatheter through tissue adjacent to the fossa ovalis 510 to access theleft atrium 504. As used herein, the tissue adjacent to the fossa ovaliscan be defined by parallel membranes or tissue generally referred to asseptum secundum (SS) and septum primum (SP). In some patients, thesetissues are fused, and thus, the catheter can be advanced to the leftatrium by passing through the fused tissues. In other patients, the SSand SP do not fully fuse and thus, a passage is defined by the SS andSP. In such embodiments, the catheter can be advanced to the left atriumby passing through the passage.

In various embodiments, a radiopaque contrast media may then be injectedthrough a lumen in the guidewire to allow visualization and ensure thatthe location of the guidewire is in the left atrium, as opposed to otherlocations, e.g., the aorta. Once the location of the guidewire isconfirmed, the catheter can be advanced into the left atrium and to theLAA, as shown in FIG. 5A.

The embodiments of FIGS. 5B-5E illustrates in more detail an operationof the apposition arms 540-1 and 540-2 in helping to bring tissues ofthe LAA together, i.e., appose tissues of the LAA. The tissue appositionmember 528 illustrated in the embodiments of FIGS. 5B-5E include theembodiment of the tissue apposition member illustrated in FIG. 3C. Invarious embodiments however, the tissue apposition members illustratedin FIGS. 3B-3F can also be used to appose tissues of the LAA.

As discussed herein, the first and second apposition arms 540-1 and540-2 can be manipulated by an operator to help position them adjacenttissues of the LAA. In addition, the first and second apposition arms540-1 and 540-2 can be manipulated to help bring the tissues of the LAAtogether. As shown in FIG. 5B, one method for bringing tissues of theLAA together can include extending the distal end 534 of the tissueapposition member 528 from the catheter 513 and positioning the distalend 534 proximal opening 578 of the LAA, as shown in FIG. 5B

Once positioned, first and second apposition arms 540-1 and 540-2 can beextended from lumens 536-1 and 536-2 at the distal end 534 of the tissueapposition member 528 using deployment rods 550-1 and 550-2 as shown inFIGS. 5B and 5C. As discussed herein, the apposition arms 540-1 and540-2 can include a predefined shape designed to pierce and hook thefirst and second apposition arms 540-1 and 540-2 within the tissues ofthe LAA so as to lodge the hooking structures 546-1 and 546-2 within thetissues, as shown in FIGS. 5B-5E.

For example, in various embodiments of FIG. 5B, the predefined shape ofthe first apposition arm 540-1 includes hooking structure 546-1 that canbe manipulated by an operator to pierce the tissue of the LAA byforcibly pushing the apposition arm 540-1 using deployment rod 550-1into the tissue. Once pierced, a barb on the hooking structure catchesthe tissue and lodges the hooking structure 546-1 within the tissue LAAso as to preclude the first apposition aim 540-1 from backing out of thetissue.

Once the first hooking structure is lodged within the tissue of the LAA,the catheter can be moved to a different location of the LAA, e.g.,opposing tissue of the LAA shown in FIG. 5C. Once the catheter 513 isproperly positioned proximal to tissue opposing tissue in which thefirst apposition arm 540-1 is lodged, the second apposition arm 540-2can be extended from lumen 536-2 of the tissue apposition member 528.The second apposition arm 540-2 can also include the predefined shape.The predefined shape of second apposition arm 540-2 can also bemanipulated to pierce the tissue of the LAA when it is extended from thetissue apposition member 528. The predefined shape of the secondapposition arm 540-2 includes the hooking structure 546-2 that can bemanipulated by an operator to pierce and hook the tissue of the LAA. Thehooking structure 546-2 can pierce the tissue of the LAA when a portionof the second apposition arm 540-2 is extended from lumen 536-2 of thetissue apposition member 528 and forcibly pushed into the tissue of theLAA using deployment rod 550-2, as shown in FIG. 5C. As discussed hereinwith respect to FIGS. 3A-3D, the deployment rods 550-1 and 550-2 can beformed of a resilient material that allows the deployment rods to flex,bend, and rotate. As shown in FIG. 5C, the first deployment rod 550-1 isshown extended from the tissue apposition member 528 in a bentconfiguration. The resiliency of the deployment rods allow the catheter513 to move to a different location of the LAA while remaining attachedto the apposition arms.

In various embodiments, the pierced tissues can be brought together byfurther manipulating the first and second apposition arms 540-1 and540-2 and/or by moving the catheter 513. For example, in variousembodiments, an operator can reposition the catheter such that it ispositioned an equal distance between the tissues in which the appositionarms 540-1 and 540-2 are lodged. Once repositioned, an operator canapply a pulling force to the apposition arms 540-1 and 540-2 topartially retract a portion of the first and second apposition arms540-1 and 540-2 into their respective lumens 536-1 and 536-2, as shownin FIGS. 5B, and 5C. As the first apposition arm 540-1 is retracting,the tissue in which the first apposition arm 540-1 is lodged is pulledtoward the distal end 534 of the tissue apposition member 528, as shownin FIG. 5D. As the second apposition arm 540-2 is retracting, the tissuein which the second apposition arm 540-2 is lodged is pulled toward thedistal end 534 of the tissue apposition member 528, as shown in FIG. 5D.An operator can continue to retract the first and second apposition arms540-1 and 540-2 until the tissues are brought together so as to contacteach other.

In various embodiments, the method for bringing the tissues together caninclude using a tissue apposition member having the suction arms thatcan apply a vacuum force to the tissues, as discussed herein withrespect to FIG. 3D. For example, the suction arms can be extended fromtheir respective lumens of the tissue apposition member and positionedadjacent tissues of the LAA. In this embodiment, a vacuum force can beapplied to the tissues and the suction arms can be retracted in theirrespective lumens to bring the tissues of the LAA together.

According to various embodiments, the methods for bringing the tissuestogether can include apposition arms having a predefined shape thatincludes the grasping structures as described herein with respect toFIG. 3B. For example, the apposition arms can be extended from theirrespective lumens of the tissue apposition member and positionedadjacent tissues of the LAA. In this embodiment, the grasping structurescan be manipulated to grab the tissues of the LAA, as the same will beknown and understood by one of ordinary skill in the art. The appositionarms can then be retracted into their respective lumens to bring thetissues of the LAA together.

In various embodiments, the methods for bringing the tissues togethercan include a single apposition arm having a predefined shape thatincludes two hooking structures as described herein with respect to FIG.3C. In this embodiment, the first hooking structure can be used topierce and hook a first tissue of the LAA and bring it toward adifferent tissue of the LAA, e.g., an opposing tissue of the LAA. Theapposition arm can then be manipulated by an operator to pierce and hookthe different tissue with the second hooking structure so as to lodgethe second hooking structure within the opposing tissue. Once the twohooking structures have been lodged in opposing tissue of the LAA, anoperator can then pull the apposition arm such that a portion of theapposition arm retracts into the lumen of the tissue apposition member.As the apposition arm retracts into the lumen, the portion of theapposition arm that diverges begins to converge as a result of beingretracted into lumen. In this embodiment, the convergence of theapposition arm helps to bring the tissues together.

Once the tissues are brought together using any of the methods describedabove, energy can be applied to the tissues. In various embodiments, themethod for fusing tissues of the LAA includes applying energy to tissueswith the energy emitting device, as described in connection with FIGS. 2and 4, to substantially occlude the opening of the LAA.

As described above, applying energy to tissues of the LAA includesapplying HIFU to the tissues. For example, in various embodiments,energy emitting device 554 can deliver HIFU to the tissues at the target580, e.g., the location in which the apposition arms brings the tissuestogether. In various embodiments, the HIFU transducer can emit HIFU witha frequency in a range of 0.8-15.0 MHz, an intensity in a range of1,000-10,000 Watt/cm², and a focus in the range of a 0.75 to 1.25 cmellipse.

In the embodiment shown in FIG. 5D, the HIFU is indicated by dottedlines originating from the HIFU transducer 556, as described inconnection with FIG. 4 (i.e., HIFU emitted from outside the human bodyto a target located within the human body). As the HIFU approaches thetarget 580 the HIFU converges until it reaches its focal point, e.g.,the apposed tissues. At the focal point, the tissues of the LAA rapidlybegin to heat and denature, as discussed herein. The position of thefocal point at target 580 relative to the HIFU transducer 556 is afunction of the geometry of the HIFU transducer and thus, the focalpoint can depend, in part, on the location of the HIFU transducerrelative to the target 580. As the reader will appreciate, the HIFUtransducer embodiment illustrated in FIG. 5D will have a different focalpoint and thus, a different geometry than a HIFU transducer configuredto apply HIFU to the target from within the human body.

As discussed herein, once the tissues are denatured, the tissues beginto renature and fuse together as they cool. In various embodiments, theprocess can be repeated to fuse the tissue at other targets if theoperator so desires. As discussed herein, the targeting device describedin FIG. 4, can be used to create, locate, define, etc., the target 580.In addition, the targeting device can be used to guide the HIFU to thetarget 580 using imaging ultrasound, MR imaging, and other components ofthe targeting device, as the same have been described herein.

Once the targeted tissues of the LAA are sufficiently denatured, theoperator can deactivate the HIFU transducer 556 and wait for the tissuesto cool. As discussed herein, when the tissues of the LAA havesufficiently cooled, they begin to renature and fuse together, as shownin FIG. 5E. An operator of the targeting device, as described inconnection with FIGS. 2 and 4, can monitor the thick and the thintissues for changes (e.g., change in temperature) to determine if thetissues have sufficiently cooled and whether they have fused together.When the operator is satisfied that tissues are sufficiently cooled andrenatured, e.g., fused together, the operator can release the appositionarms 540-1 and 540-2 from the tissue apposition member by detaching themfrom the deployment rod, as discussed herein. In these embodiments, oncereleased, the first and second apposition arms 540-1 and 540-2 are leftlodged within the tissue of the LAA until they biodegrade and areabsorbed by the human body.

FIGS. 6A-6C illustrate another embodiment of methods for fusing tissuesof a left atrial appendage by bringing tissues of the LAA together andfusing the tissues with an energy emitting device located outside thehuman body.

In various embodiments, the catheter 613 can be advanced to the LAAusing the same methods as those described with respect to FIG. 5A. Oncethe catheter 613 is positioned proximal to the LAA, the distal end 618of the catheter 613 can be positioned such that the tissue appositionmember 628 and the closure sheath 629 are centered relative to theopening of the LAA when those components are extended from the distalend 618 of the catheter 613, as shown in FIG. 6A. As discussed herein,the targeting device and various components of the targeting devicediscussed with respect to FIG. 4 can be implemented to assure properpositioning and alignment of the catheter 613 and the various componentstherein.

The embodiments of FIGS. 6B and 6C illustrates in more detail anoperation of the apposition arms 640-1 and 640-2 in helping to bringtissues of the LAA together, i.e., appose tissues of the LAA. The tissueapposition member 628 illustrated in the embodiments of FIGS. 6B and 6Cinclude the embodiment of the tissue apposition member 328 illustratedin FIGS. 3E-3G.

Once the distal end 618 of the catheter 613 has been properlypositioned, as discussed in FIG. 6A, the closure sheath 629 can beretracted toward the proximal end 632 of the elongate body 630 of thetissue apposition member 628 to release the apposition arms 640-1 and640-2. As discussed herein with respect to FIGS. 3E and 3F, when theapposition arms 640-1 and 640-2 are released, they spring radially awayfrom the longitudinal axis of the tissue apposition member in oppositedirections. As shown in FIG. 6B, the spring like properties of theapposition arms 640-1 and 640-2 engage opposing tissue of the LAA bypiercing and hooking the tissue when the apposition arms are released soas to lodge the hooking structures 646-1 and 646-2 within the opposingtissues.

Once the hooking structures have engaged the tissue of the LAA, theclosure sheath 629 can be used to draw apposition arms 640-1 and 640-2together by sliding the closure sheath 629 along the longitudinal axisof the tissue apposition member 628 toward the hooking structures 646-1and 646-2 as shown in FIG. 6C. In various embodiments, the inner surface633 of the closure sheath 629 compresses the apposition arms 640-1 and640-2 toward each other and the engaged tissue with them. In variousembodiments, the operator can continue sliding the closure sheath towardthe hooking structures until opposing tissue contacts each other. Oncethe operator is satisfied that the opposing tissues are sufficiently incontact, the operator can lock the closure sheath to preclude thetissues from moving away from each other and apply energy to the tissue(i.e., target 680) with the energy emitting device to substantiallyocclude the opening of the LAA, as described above in the embodiments ofFIGS. 5A and 5E.

While the present disclosure has been shown and described in detailabove, it will be clear to the person skilled in the art that changesand modifications may be made without departing from the scope of theinvention. As such, that which is set forth in the foregoing descriptionand accompanying drawings is offered by way of illustration only and notas a limitation. The actual scope of the invention is intended to bedefined by the following claims, along with the full range ofequivalents to which such claims are entitled.

In the foregoing Detailed Description, various features are groupedtogether in several embodiments for the purpose of streamlining thedisclosure. This method of disclosure is not to be interpreted asreflecting an intention that the embodiments of the invention requiremore features than are expressly recited in each claim. Rather, as thefollowing claims reflect, inventive subject matter lies in less than allfeatures of a single disclosed embodiment. Thus, the following claimsare hereby incorporated into the Detailed Description, with each claimstanding on its own as a separate embodiment.

What is claimed is:
 1. A catheter for delivering energy to fuse cardiactissue, comprising: an elongate body having a first lumen having a firsttissue apposition member and a second lumen having a second tissueapposition member, wherein the first and second tissue appositionmembers are extendably positioned within the elongate body to apposecardiac tissue; and an energy emitting device extendably positioned atleast partially within the elongate body where the energy emittingdevice can emit energy to fuse the apposed cardiac tissue, wherein theenergy emitting device and the first and second tissue appositionmembers are each independently extendable within the elongate body. 2.The catheter of claim 1, where the energy emitting device is a highintensity focused ultrasound (HIFU) transducer configured to emit HIFUto a target from within the human body.
 3. The catheter of claim 2,where the HIFU transducer is formed of a piezoelectric material thatdeforms and emits HIFU when an electrical potential is supplied to theHIFU transducer.
 4. The catheter of claim 2, where the energy emittingdevice can emit both HIFU and low intensity ultrasound.
 5. The catheterof claim 1, where the energy emitting device can emit low intensityultrasound.
 6. The catheter of claim 1, where the energy emitting devicecan emit RF energy.
 7. The catheter of claim 1, where the energyemitting device can emit cryogenic energy.
 8. The catheter of claim 1,where the energy emitting device can emit laser energy.
 9. The catheterof claim 1, where the energy emitting device can emit resistive heatenergy.
 10. The catheter of claim 1, where the energy emitting devicecan emit microwave energy.
 11. The catheter of claim 1, wherein thefirst tissue apposition member and the second tissue apposition membereach comprise a structure that is selected from the group consisting ofhooking structures, grasping structures, and suction arm structures. 12.The catheter of claim 1, wherein the first tissue apposition member andsecond tissue apposition member are optionally releasably coupled to theelongate body.
 13. An occlusion apparatus for delivering energy to fusecardiac tissue, comprising: a catheter having an elongate body having afirst lumen having a first tissue apposition member and a second lumenhaving a second tissue apposition member, wherein the first and secondtissue apposition members are extendably positioned within the elongatebody to appose cardiac tissue, an energy emitting device extendablypositioned at least partially within the catheter, wherein the energyemitting device and the first and second tissue apposition members areeach independently extendable within the elongate body, and conductorscoupled to the energy emitting device; and a signal generator coupled toan amplifier, where the conductors carry an electrical signal from thesignal generator coupled to the amplifier to the energy emitting devicethat emits energy to fuse the apposed cardiac tissue.
 14. The occlusionapparatus of claim 13, where the energy emitting device is a highintensity focused ultrasound (HIFU) transducer configured to emit HIFUto a target from within the human body.
 15. The occlusion apparatus ofclaim 14, where the HIFU transducer is formed of a piezoelectricmaterial that deforms and emits HIFU when an electrical potential issupplied to the HIFU transducer.
 16. The occlusion apparatus of claim14, where the HIFU transducer has a concave shape that focuses the HIFUto a focal point.
 17. The occlusion apparatus of claim 14, where theenergy emitting device can emit both HIFU and low intensity ultrasound.18. A catheter for delivering energy to fuse cardiac tissue, comprising:an elongate body having a first lumen having a first tissue appositionmember and a second lumen having a second tissue apposition member,wherein the first and second tissue apposition members are extendablypositioned within the elongate body to appose cardiac tissue; and anenergy emitting device extendably positioned at least partially withinthe elongate body where the energy emitting device can emit energy tofuse the apposed cardiac tissue, where the energy emitting device is ahigh intensity focused ultrasound (HIFU) transducer having a concaveshape configured to emit HIFU at a focal point within the human body,and further wherein the energy emitting device and the first and secondtissue apposition members are each independently extendable within theelongate body.
 19. The catheter of claim 18, where the HIFU transduceris formed of a piezoelectric material that deforms and emits HIFU whenan electrical potential is supplied to the HIFU transducer.